Metabolic and hormonal agents produce changes in the heart and circulatory system faster than autonomic neural transmission

F

The aortic valve obstructs coronary blood flow by pushing against the openings of the coronary arteries during systole.

T

Although both produce vasoconstriction, the effects of norepinephrine are quantitatively more vasoconstrictive than the effects of epinephrine.

T

1. Which of the following statements does not accurately describe the pericardium?a.It is a double-walled membranous sac that encloses the heart.b.It is composed of connective tissue and a surface layer of squamous cells.c.It protects the heart against infection and inflammation from the lungs and pleural space.d.It contains pain and mechanoreceptors that can elicit reflex changes in blood pressure and heart rate.

t is composed of connective tissue and a surface layer of squamous cells.

2. Which cardiac chamber has the thinnest wall and why?a.The right and left atria because they are low-pressure chambers that serve as storage units and conduits for bloodb.The right and left atria because they are not involved directly in the preload, contractility, or afterload of the heartc.The left ventricle because the mean pressure of blood coming into this ventricle is from the lung, which has a low pressured.The right ventricle because it pumps blood into the pulmonary capillaries, which have a lower pressure compared with the systemic circulation

The right and left atria because they are low-pressure chambers that serve as storage units and conduits for blood

4. The mitral and tricuspid valves close after the ventricles are filled with blood because the:a.chordae tendineae relax, which allows the valves to close.b.increased pressure in the ventricles pushes the valves to close.c.trabeculae carneae contract, which pulls the valves closed.d.reduced pressure in the atria creates a negative pressure that pulls the valves

increased pressure in the ventricles pushes the valves to close.c.

5. A function of the papillary muscles is to _____ valves.a.close the semilunarb.prevent backward expulsion of the atrioventricular.c.close the atrioventriculard.open the semilunar

prevent backward expulsion of the atrioventricular.

6. During the cardiac cycle, the aortic and pulmonic valves close after the ventricles contract because the:a.papillary muscles relax, which allows the valves to close.b.chordae tendineae contract, which pulls the valves closed.c.reduced pressure in the ventricles creates a negative pressure, which pulls the valves closed.d.blood fills the cusps of the valves and causes the edges to merge, closing the valves.

blood fills the cusps of the valves and causes the edges to merge, closing the valves.

8. The significance of the "atrial kick" is that it is the contraction of the:a.right atria that is necessary to open the tricuspid valve.b.right atria that is necessary to increase the blood volume from the venae cavae.c.left atria that increases the blood volume into the ventricle.d.left atria that is necessary to open the mitral valve.

left atria that increases the blood volume into the ventricle.

9. Occlusion of the left anterior descending artery during a myocardial infarction would interrupt blood supply to the:a.left and right ventricles and much of the interventricular septum.b.left atrium and the lateral wall of the left ventricle.c.upper right ventricle, right marginal branch, and right ventricle to the apex.d.posterior interventricular sulcus and smaller branches of both ventricles.

left and right ventricles and much of the interventricular septum.

10. Occlusion of the circumflex artery during a myocardial infarction would interrupt blood supply to the:a.left and right ventricles and much of the interventricular septum.b.posterior interventricular sulcus and smaller branches of both ventricles.c.upper right ventricle, right marginal branch, and right ventricle to the apex.d.left atrium and the lateral wall of the left ventricle

left atrium and the lateral wall of the left ventricle

11. The coronary ostia is located in the:a.left ventricle..b.aortic valve.c.coronary sinus.d.aorta.

14. The function of P cells found in the sinoatrial node and Purkinje fibers is that they:a.are receptors for pain stimuli, such as the pain that occurs during infarction.b.prolong the refractory period before the next contraction.c.are assumed to be the site of impulse formation.d.initiate repolarization of the myocardium.

are assumed to be the site of impulse formation.d.

15. Depolarization of a cardiac muscle cell occurs as the result of a:a.decrease in the permeability of the cell membrane to potassium.b.rapid movement of sodium into the cell.c.decrease in the movement of sodium out of th

rapid movement of sodium into the cell.

16. Which of the following events occurs during phase 1 of the normal myocardial cell depolarization and repolarization?a.Repolarization when potassium moves out of the cellsb.Repolarization when sodium rapidly enters into cellsc.Early repolarization when sodium slowly enters cellsd.Early repolarization when calcium slowly enters cells

18. In the normal electrocardiogram, the PR interval represents:a.atrial depolarization.b.ventricular depolarization.c.atrial activation to onset of ventricular activity.d."electrical systole" of the ventricles

atrial activation to onset of ventricular activity

19. The cardiac electrical impulse normally begins spontaneously in the sinoatrial (SA) node because:a.of its superior location in the right atrium.b.it is the only area of the heart capable of spontaneous depolarization.c.it has rich sympathetic innervation via the vagus nerve.d.it depolarizes more rapidly than other automatic cells of the heart.

it depolarizes more rapidly than other automatic cells of the heart.

20. The _____ period follows depolarization of the myocardium and represents a period during which no new cardiac potential can be propagated.a.refractoryb.hyperpolarizationc.thresholdd.SA

22. Which of the following can shorten the conduction time of action potential through the atrioventricular (AV) node?a.Parasympathetic nervous systemb.Catecholaminesc.Vagal stimulationd.Sinoatrial node (SA)

Catecholaminesc.

23. If the sinoatrial (SA) node fails, at what rate can the atrioventricular (AV) node polarize?.a.60 to 70 per minuteb.40 to 60 per minutec.30 to 40 per minuted.10 to 20 per minute

40 to 60 per minute

24. What, if any, is the effect of epinephrine on β2a. -receptors of the heart?There is no effectb.Dilate coronary arteriolesc.Increase the strength of myocardial contractiond.Decrease the heart rate

Dilate coronary arterioles

25. Where are the receptors for neurotransmitters located in the heart?a.Semilunar and atrioventricular valvesb.Endocardium and sinoatrial nodec.Myocardium and coronary vesselsd.Epicardium and atrioventricular node

27. Within a physiologic range, an increase in left ventricular end-diastolic volume (preload) leads to a(n):a.increased force of contraction.b.decrease in refractory time.c.increase in afterload.d.decrease in repolarization.

increased force of contraction.

28. As stated by the Frank-Starling law, there is a direct relationship between the _____ of the blood in the heart at the end of diastole and the _____ of contraction during the next systole.a.pressure; forceb.volume; strengthc.viscosity; forced.viscosity; strength

volume; strength

29. Pressure in the left ventricle must exceed pressure in the _____ before the left ventricle can eject blood.a.superior vena cavab.aortac.inferior vena cavad.pulmonary veins

31. When the volume of blood in the ventricle at the end of diastole increases, the force of the myocardial contraction during the next systole will also increase. This is an example of which law or theory about the heart?a.Laplace's lawb.Poiseuille's formulac.Cross-bridge theoryd.Frank-Starling law

Frank-Starling law

32. The resting heart in a healthy person is primarily under the control of the _____ nervous system.a.sympatheticb.parasympatheticc.somaticd.spinal

parasympathetic

33. The Bainbridge reflex is thought to be initiated by sensory neurons in the:a.atria.b.aorta.c.sinoatrial node.d.ventricles.

atria.

34. The correct sequence of events that occur after the baroreceptor reflex is stimulated is that the impulse is transmitted from the carotid artery to the:a.vagus nerve to the medulla to increase parasympathetic activity and decrease sympathetic activity.b.glossopharyngeal cranial nerve through the vagus nerve to the medulla to increase sympathetic activity and decrease parasympathetic activity.c.glossopharyngeal cranial nerve through the vagus nerve to the medulla to.increase parasympathetic activity and decrease sympathetic activity.d.glossopharyngeal cranial nerve through the vagus nerve to the hypothalamus to increase parasympathetic activity and decrease sympathetic activity.

glossopharyngeal cranial nerve through the vagus nerve to the medulla to increase sympathetic activity and decrease parasympathetic activity.

35. Reflex control of total cardiac output and total peripheral resistance is controlled by:a.parasympathetic stimulation of the heart, arterioles, and veins.b.sympathetic stimulation of the heart, arterioles, and veins.c.autonomic control of the heart only.d.somatic control of the heart, arterioles, and veins

b.sympathetic stimulation of the heart, arterioles, and veins.

36. Myogenic regulation of blood vessel diameter and subsequent blood flow through a vessel is an example of _____ of blood vessels.a.autonomic regulationb.somatic regulationc.autoregulationd.metabolic regulation37. The right lymphatic duct drains

where is major cardiovascular center in the central nervous system?.Frontal lobeb.Thalamusc.Brainstemd.Hypothalamus

Brainstem

39. What is an expected change in the cardiovascular system that occurs with aging?a.Arterial stiffeningb.Decreased left ventricular wall tensionc.Decreased aortic wall thicknessd.Arteriosclerosis

Arterial stiffening

The major determinant of the resistance that blood encounters as it flows through the systemic circulation is the:.a.volume of blood in systemic circulation.b.muscle layer of the metarterioles.c.muscle layer of arterioles.d.force of ventricular contraction

muscle layer of arterioles.

41. Which statement is false concerning the method in which substances pass from capillaries and the interstitial fluid?a.Substances pass through junctions between endothelial cells.b.Substances pass through pores or oval windows (fenestrations).c.Substances pass through vesicles by active transport across the endothelial cell membrane.d.Substances pass through by osmosis across the endothelial cell membrane.

Substances pass through by osmosis across the endothelial cell membrane.